The present invention relates to resilient wheels and brake mechanisms therefor. More particularly, the present invention relates to brake mechanisms adapted for use in connection with resilient wheels having generally concentric inner and outer wheel portions that are connected to one another by resilient members in a manner to permit resilient, shock-absorbing movement between the inner and outer wheel portions.
In general, resilient wheels comprising an inner hub and an outer wheel portion resiliently connected to one another are known in the art. In such resilient wheels, the inner hub and outer wheel portion are typically connected to one another by a plurality of resilient spring members in a manner to permit resilient movement of the outer wheel portion relative to the hub to absorb shock and to displace external loads. Many such resilient wheels were designed in the early 1900""s in response to rapid growth of the automobile industry. A primary goal of such designs was to provide a means for absorbing shock and providing a smoother ride, in a time before pneumatic automobile tires were prevalent.
Resilient wheels of this type have not been effectively used in connection with bicycles. This is partly because conventional caliper-style bicycle brake mechanisms are not particularly suited for use with such resilient wheels. In general, conventional caliper-style bicycle brake mechanisms have brake pads that are positioned adjacent the outer rim of the bicycle wheel for frictional engagement therewith. However, the outer wheel rim of a resilient wheel does not have a fixed path of rotation relative to the hub and axle. In general, the inner hub of a resilient wheel is mounted for rotation about the axle. The outer wheel portion is connected to the hub by resilient spring members in a manner to permit resilient movement of the outer wheel portion relative to the hub. This resilient movement of the outer wheel portion allows the outer wheel portion to be displaced relative to the inner hub in response to external loads. Thus, the outer wheel rim of a resilient wheel does not have a fixed path of rotation like the rim of a conventional bicycle wheel with rigid spokes and, consequently, conventional caliper-style bicycle brake mechanisms that engage with the outer wheel rim are not suitable for use with resilient wheels.
It is an object of the present invention to provide a brake mechanism suitable for use with resilient wheels. A more specific object of the invention is to provide a brake mechanism adapted for use with a resilient wheel in a manner that permits resilient displacement of an outer wheel portion relative to an inner wheel portion of the resilient wheel. Another object of the invention is to provide a cam action brake mechanism adapted for use with both resilient wheels and conventional wheels.
In general, a wheel and brake system of the present invention comprises an inner wheel, an outer wheel and a brake mechanism. The inner wheel is adapted to be rotatably mounted to a vehicle. The outer wheel is positioned generally concentric with the inner wheel. A plurality of resilient members connect the inner and outer wheel to one another in a manner to permit resilient movement of the outer wheel relative to the inner wheel. The brake mechanism comprises a mounting block, a lever arm and a cam follower. The mounting block is adapted to be mounted to the vehicle adjacent the inner wheel. The lever arm is pivotally connected to the mounting block in a manner to permit pivoting movement of the lever arm relative to the mounting block. The lever arm is movable relative to the mounting block between a braking position and a non-braking position. The lever arm includes a cam surface. The cam follower is connected to the mounting block in a manner to permit reciprocating movement of the cam follower relative to the mounting block. The cam follower is movable relative to the mounting block between a wheel-engaging position and a disengaged position. The cam follower has a cam engaging portion that is adapted for camming engagement with the cam surface of the lever arm in a manner so that movement of the lever arm from its non-braking position toward its braking position causes movement of the cam follower from its disengaged position toward its wheel-engaging position. The cam follower has a wheel-engaging portion that is adapted for frictional engagement with the inner wheel when the cam follower is in its wheel-engaging position.
In another aspect of the invention, a wheel and brake system comprises an inner wheel, an outer wheel positioned generally concentric with the inner wheel, a plurality of resilient members connecting the inner and outer wheels to one another for resilient relative movement, and a brake mechanism. The brake mechanism includes a mounting member adapted to be mounted to the vehicle, first and second lever arms, and an actuating member. The first lever arm is pivotally connected to the mounting member in a manner to permit pivoting movement of the first lever arm relative to the mounting member between a braking position and a non-braking position. Similarly, the second lever arm is pivotally connected to the mounting member in a manner to permit pivoting movement of the second lever arm relative to the mounting member between a braking position and a non-braking position. The first lever arm has a first wheel-engaging portion adapted for frictional engagement with a first side of the inner wheel when the first lever arm is in its braking position. Similarly, the second lever arm has a second wheel-engaging portion adapted for frictional engagement with a second side of the inner wheel when the second lever arm is in its braking position. The actuating member is operatively connected to the first and second lever arms in a manner to cause movement of the first and second lever arms from their respective non-braking positions to their respective braking positions.
A cam action brake mechanism of the present invention comprises a mounting block, a lever arm and a cam follower. The mounting block is adapted for mounting the brake mechanism to a vehicle. The lever arm is pivotally connected to the mounting block in a manner to permit pivoting movement of the lever arm relative to the mounting block between a braking position and a non-braking position. The lever arm includes a cam surface. The cam follower is connected to the mounting block in a manner to permit reciprocating movement of the cam follower relative to the mounting block between a wheel-engaging position and a disengaged position. The cam follower has a cam engaging portion that is adapted for camming engagement with the cam surface of the lever arm in a manner so that movement of the lever arm from its non-braking position toward its braking position causes movement of the cam follower from its disengaged position toward its wheel-engaging position. The cam follower has a wheel-engaging portion adapted for frictional engagement with a wheel of the vehicle when the brake mechanism is mounted to the vehicle and when the cam follower is in its wheel-engaging position.
While the principal advantages and features of the present invention have been described above, a more complete and thorough understanding and appreciation for the invention may be attained by referring to the drawings and description of the preferred embodiments, which follows.